Staylogs for use with veneer slicers are known. Such staylogs hold a flitch and move relative to a slicing knife. As the flitch passes the knife, the knife slices a sheet of veneer from the flitch.
The veneer slicers use a plurality of dogs to hold the flitch in position against a mounting surface on the staylog. The dogs are clamping members that extend from the mounting surface of the staylog and are positioned on either side of the flitch along the length of the staylog. Typically, the dogs include a sharp-edged portion oriented parallel to the mounting surface of the staylog to cut into the flitch and hold it in place against the staylog. The dogs are moved toward each other to pinch the flitch therebetween.
An alternative dogging arrangement is disclosed in U.S. Pat. No. 5,150,746 to Weil. Weil discloses a plurality of oval-shaped rotating dogs that include a sharp-edged portion at the ends of the major axis of the oval. The dogs are arranged in parallel rows along the mounting surface of the staylog. A plurality of axially extending grooves are cut into the mounting surface of the flitch. The grooves are cut to align with the rows of dogs and are sized to allow the dogs to fit up into the grooves when the major axis of the oval is aligned with the groove. When the flitch is mounted on the staylog, the oval-shaped dogs extend upwardly into the grooves and are rotated to engage the sharp-edged portion of the dogs with the flitch.
Regardless of whether clamping dogs or rotating dogs are used, conventional flitch mounting techniques require that the flitch mounting surface be positioned adjacent the staylog mounting surface. Unfortunately, these conventional mounting techniques cause some of the best veneer on a log to be wasted.
A flitch is formed by cutting a log down the middle along its longitudinal axis so that the plane formed by the cut defines a flitch mounting surface and the periphery of the log defines a veneer-producing surface. Conventionally, the mounting surface of the flitch is positioned adjacent the mounting surface of the staylog and the veneer-producing outer portion of the log is positioned to be sliced into sheets of veneer by the knife.
In a rotary veneer slicer, however, because the tree trunk is naturally tapered, one end of the flitch is thicker than the other end, and consequently extends a greater distance from the mounting surface of the staylog. As a result, the veneer-producing zone of the flitch is frusto-conical, i.e., trapezoidal in cross-section when viewed from the side of the flitch or from the knife. As the staylog and the flitch are rotated in a rotary veneer slicer, the knife first encounters the thickest portion of the flitch. With each rotation, the knife slices a wider veneer sheet until the entire length of the flitch is exposed to the knife. Once the entire length of the flitch is being sliced, subsequent sheets are of substantially uniform width. However, the initial sheets, which are cut from the best part of the log, are too narrow to be useful, and are thrown away as wasted product. Consequently, some of the best veneer on a flitch is thrown away as waste. In addition, with the prior art methods of retention, the long slots formed along the length of the flitch removed sufficient material from the flitch that the flitch lost its rigidity and would flex in response to the pressure of the slicing knife resulting in, at best, nonuniform and unacceptable slices of veneer.
Therefore, a need exists for a method and apparatus for mounting a flitch on a staylog in such a manner that the flitch is securely retained on the staylog, that the production of desirable veneer from the outside of the flitch is increased and waste is reduced, and that waste is concentrated in the less desirable, inner portion of the flitch.